Telephone system



R. SCHENK TELEPHONE SYSTEM June 24; 1930.

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Filed Oct. 20, 1928 Mal Q Q I ATTORNEY Patented June 24, 1930 UNITEDSTATES ",1' ATENT 1 OFFICE RUDOLF SCHENK, or VIENNA, AUSTRIA,AssiernoETo wEsTEE-n ELEoTEIc COMPANY,

INCORPORATED, on NEW YORK, N. Y., A. CORPORATION-01E" NEW YORK TELEPHONESYSTEM; l

Application filed. October 20, 1928, Serial No. graces, and inAustriaiMay' 14, 1926.

This invention relates to telephone systems and particularly to busysignaling arrangements for manual common battery systems.

In accordance with common practice a manual operator tests for the idleor busy condition of a called line by touching the tip of the callingplug to the sleeve of the multiple jack of the called line. If suchcalled line is busy the result of this test is a click produced in theoperators receiver. The operator may then report the busy conditionfound to the calling subscriber either orally or by plugging into a busyback jack. Either of these operations consumes time and ultimatelyresults in the employment of a large operating force.

According to the present invention the busy signaling arrangement fornotifying the calling subscriber that the called line is busy isassociated with the cord circuit and is started into operation upon theusual busy test being made. Thus when the tip of the calling plug istouched to the sleeve of a. busy line jack, the busy back arrangement isimmediately brought into action and signals both the calling subscriberand the operator that the called line is busy and maintains this signaluntil the connection to the calling subscriber is taken down.

The drawing is a diagrammatic illustration of the present invention.

Connection is established to the calling subscriber by inserting theplug A. S. of an idle connecting cord into the jack K. a. Thereby thefollowing circuit is closed: earth over winding of relay T. R, jacksleeve and 0 contact of the plug, winding of relay A. R. over contact 3of relay S. R. to battery. Relay T. R. and relay A. R. are caused tooperate. The operators telephone is connected to the callingsubscriberat the contacts 1 and 3 of the relay A. B. When the operator has learnedthe wanted number she puts the tip S. of the connecting plug V. S. tothe sleeve H of the jack of the called line. If the called line is busyi. e. if the plug of another connecting cord KO II has been inserted inanother multiple jack Kb then the plug tip S will connect battery overthe C-wire and winding ofrelay'S. R. of the con necting cord KO II tothe winding of relay B. R. over contact 1 of SR. While the connectionbetween plug tip S. and jack sleeve '11 is maintained relay B. R. isenergized and its contact '1 is closed, whereby battery is connectedtothe winding W I of relay SU. R. Relay 'SU. R. becomes energized andlocks in a circuit from ground, winding W II of relaySU. R. and itscontact 4, contact 2 of relay A. R. to battery. Consequently when theplug tip S. is removed from connection with the jack sleeve H and relayB. R. returns to normal, relay SU. R. will remain energized.

At contact 1 of SU. R. a circuit is closed for busy lamp BL. so that theoperator has a visual indication that the called line is busy. Contact 2of relay SU. R. connects a source of tone SU. to the connecting point Sfrom,. which tone current flows over contact 3 of relay A. R, ringcontact'R of plug A. S., the a wire of the calling telephone line, thereceiver at substation SP., the Z2 wire, tip

contact S of plug A. S. and winding of retardation coil D. S. tobattery. The subscriber at substation SP. hears this tone and is therebysignalled that the called line is busy.

Tone current applied to the connecting point S; also flows over theoperators telephone T., condenser K, secondary winding of induction coilI. S., high resistance Wz', contact 1 of relay A. R. and winding ofretardation coil D. S. to battery. The opera-' tor receives this tonesignal weakened by the high resistance Wi.

The operator now removes the answering plug A. S. from the jack. Therebyrelay A. R. is deenergized and returns to normal. Contact 2 of relay A.R. disconnects battery from the holding winding W 11 of relay SU. R.which thereupon returns to normal. Contacts 1 and 2 of relay A. R. openand the visual and audible busy signals are out OK; Contact 3 of relayA. R. closes and short circuits the high resistance W2 in series withthe operators telephone set.

What is claimed is: y

1. In a telephone system, a calling line, a I

circuit terminating at one end in a connection to said calling line andat another end in a cord and plug, a source of tone current, a busy lampand an operators set associated with said circuit, a called lineterminating in a jack, and means responsive to a transient connectionbetween'the tip of saidplug and the sleeve of said called line jack forconnecting said source of tone current to said calling line and saidoperators' set and for lighting said busy lamp. I

2. In a telephone system, a calling line, a circuit terminating at oneend in a connection to said calling line and at another end in a cordand plug, a source'of tone current and an operators jset associated withsaid circuit, a called line terminating in a jack,

means responsive to a transient connection between the tip of said plugand the sleeve of said called line jack for connecting said source oftone current to said calling line and said operators set and means forattenuating the tone current 1n said operators set.

RUDOLF SCHEN K.

